The Geissele Super Semi-Automatic (SSA®) is a 4.5lb non-adjustable combat trigger that is a precision two-stage trigger and allows precise and accurate trigger control. The SSA’s two-stage design allows the trigger to be light enough for accurate and precise shots, but forgiving enough for CQB. The SSA is safety certified by Crane Naval Surface Warfare Center. It is recommended for demanding applications such as Law Enforcement use, Close Quarters Battle (CQB) and mid-range carbine work. Mil-Spec pin size